Such vehicle rear seats are used especially in passenger and multipurpose vehicles having a cargo space behind the back rest which can be enlarged by folding the back rest down. In modern vehicles, in order to increase the comfort, the back rest is divided in the center or off center, and the back rest parts are individually capable of being unlocked and folded back.
Generally in such back rests, however, the danger exists that in the case of an extreme load, especially in the case of a rear or front collision, the free ends of the back rest parts will be unable to withstand the pressure on the cargo space in the region of the division plane. The back rest parts may undergo deformation (especially in the central region of the back rest), resulting in the release of the locks on the side wall.
To reduce this danger, it is known that an additional locking device for the releasable locking of the two back rest parts to one another can be arranged in the plane of division, said locking device being on the side wall and the additional locking device being connected by an activation rod for simultaneous activation.
This additional locking device, however, offers effective protection only if both back rest parts are locked together and to the side wall. As soon as one back rest part is in the folded position, the additional locking device no longer provides protection.